Integrated Assessment of Emerging Contaminants (Microplastics and Pfas) in Nigerian Freshwater Systems: A Review of Implications on Ecotoxicology and Human Health

Abstract

Microplastics (MPs) and per- and polyfluoroalkyl substances (PFAs) pose more and more risks to freshwater ecosystems and overall human health, especially in Nigeria where communities depend heavily on surface waters, and the available data on these contaminants remain limited. This study reviews existing evidence on the occurrence, eco-toxicological implications, the dangers to health associated with MPs and PFAS in Nigerian freshwater systems. A qualitative narrative review was conducted using peer-reviewed studies, reports, and regional investigations focusing on freshwater organisms, sediments, and water matrices. Emphasis was placed on bioindicator studies, analytical techniques, and exposure pathways. Findings indicate widespread microplastic contamination in Nigerian rivers, with fibers and films of polyethylene, polypropylene, and nylon detected in freshwater invertebrates and water samples at eco-toxicologically significant levels. Transfers to fishes from the affected organisms are made possible because of their position on the cycle of feeding for aquatic organisms. PFAs data are comparatively scarce but confirm detectable concentrations in water, sediments, and wastewater sludge, underscoring their persistence and bioaccumulative potential. Evidence suggests potential sub-lethal ecological effects and plausible human exposure through drinking water and fish consumption. MPs and PFAS represent a growing environmental and public health concern in Nigeria. Despite limited local data, existing evidence supports the need for precautionary management, expanded monitoring, and integrated eco-toxicological and health-focused research to mitigate future risks